Operational definitions were a neo-Machean development that connected with the positivism of Logical Positivism. Logical Positivism failed, with the failure of operational definitions being just one of multiple and multifarious failures of Logical Positivism more broadly. Operationalism, however, has continued to seduce psychology more than half a century after it was repudiated by philosophers of science, including the very Logical Positivists who had first taken it seriously. It carries with it a presupposed metaphysics that is false in virtually all of its particulars, and thereby distorts and obscures genuine issues concerning the nature of theory and of science. It makes it particularly difficult for psychologists, under the thrall of this dogma, to free themselves from these false presuppositions, and to think about, create, and critique genuine scientific theory and process. That is the tragedy of operationalism.